INDIVIDUAL REDOX CHARACTERISTICS AND KINETIC-PROPERTIES OF THE HEMES IN CYTOCHROMES C(3) - NEW METHODS OF INVESTIGATION

The elucidation of the role of the four hemes in cytochromes c(3) requ ires several complementary approaches. The measurement and the assignm ent of the redox potentials resort to magnetic spectroscopies, EPR and NMR, which are able to discriminate the hemes. The origin of the diff erences between the redox properties of the hemes can be studied by co mparing their thermodynamic parameters Delta S and Delta H, as measure d by the temperature dependence of their individual potentials. Lastly , the available data concerning the electron exchange between cytochro mes c(3) and their redox partners can be analysed through a detailed k inetic model which provides important information on the role of the d ifferent hemes.